Ammunition



Unite 2,915,9'2 1C@ Patented Dees-,1959

AMMUNITIoN "Aaron L. Hitchens, North Ridge, Calif., and Emil Czapek,

Woodbridge, Conn., assignors to Olin Mathieson Chemical Corporation,East Alton, Ill., a corporation of Virginia Application December 2,1955, Serial No. 550,570

lThis invention relates generally to ammunition and more particularly togun cartridges and to a method for making the same.

In the manufacture of shotgun cartridges, it has been the custom,heretofore, to make the case from a relatively pliant and resilientconvolute wound paper tube and a metallic head which closes one end ofthe tube. This type of cartridge is not entirely satisfactory, however,because the region of the tubular body adjacent the metallic head andparticularly substantially adjacent to the ange or extraction rim of thehead sometimes expands when the cartridge is fired rendering extractionthereof from the gun chamber extremely dicult. In fact, in someinstances the head becomes detached from the tubular body by the gunsextraction mechanism. In other instances, the friction between thecartridge case and the guns chamber is so great that none of thecartridge case can be removed by the average guns extracting mechanism.'Ihese disadvantages of such a cartridge are hazardous as well astroublesome to the shooter for it sometimes happens that a cartridge isinserted and red in the chamber of a gun which contains the'tubular bodyof a preceding cartridge often with serious injury to the shooter.-

In view of these disadvantages of the paper shotgun cartridge having ametallic head, many attempts have been made to overcome this defectivecondition. It has been recognized that the expansion or bulging of thebreech end of the cartridge case is due to the pressure of the gasesdeveloped by the explosion of the propellent charge and numerousexpedients therefor have been proposed. Probably the most successful ofthese is the prov vision of an abturating basewad within the tubularbody and adjacent the metallic head thereof,but even the best of thesewads may fail to completely seal the breech portion of the cartridgeagainst gas leakage. It has also been suggested, as for example, in U.S.Patent 1,171,313 issued to Bonham, February 8, 1916, that one end of thetubular body be folded about the end of the basewad and that the tubewall be forced into the extraction rim or ange of the metallic head bymeans of a metallic disk. This expedient has not been completelysuccessful, however, as it involves a rather cumbersome manufactoringstep and does not eliminate separation of theY head from the tubularbody when the cartridge is red.

Numerous other shotgun cartridge cases have been proposed includingcases molded from various plastic or synthetic resinous compositions orcases molded from paper pulp or papier mach but none have been foundvshotgun cartridge having the advantages of the usual paper cartridge butdevoid of the disadvantagesrinherent with the prior construction. Afurther object of this invention is to provide a method for making anovel shotgun cartridge case having a paper tubular body. A stillfurther object is to provide an improved case for shotgun cartridges.

Other objects will become apparent from the following description andaccompanying drawing in which:

Figure 1 illustrates, in a vertical view in section, suitable apparatusfor making an embodiment of this invention, and

Figure 2 is a vertical sectional View of a cartridge illustrating anembodiment of this invention made in apparatus such as illustrated inFigure 1.

Invaccordance \with this invention, generally stated, the foregoingobjects as well as others are achieved by providing a shotgun cartridgewith a plastic head and a paper tubular body havingione end thereoffolded inwardly and embedded in the plastic head, thereby securelylocking the tube and head together. This invention also provides amethod for forming the plastic head about and in locking engagement withone end of the tubular body in such a way that the head isnot removedfrom the tubular body by the extraction mechanism of the gun. By plastichead or base as utilized herein and in the appended claims is meant ahead formed from a resinous material which can be shaped in a softenedstate and hardened thereafter. Either a thermoplastic or a thermosettingtype resin is suitable for the purpose provided that the required periodof time at the molding or casting temperature thereof is below thatpoint at which the properties of the paper tubewill be deleteriouslyalfected.

In general,` in making the cartridge case of this invention, a papertube is convolutely wound using a suitable adhesive such as casein orstarch, Waterproofed and sized in accordance with known processes. Thebasewad is positioned within the tube so that it is spaced away from theend and that portion of the tube extending from the bottom of thebasewad is subsequently folded rover and about the external edges of thebottom of the Wad; it being preferred that the angle of the bend be lessthan ninety degrees for the usual flat-bottomed wad illusl trated, i.e.that angle which leaves the folded end spaced from the wad as shown. Ashotgun cartridge head or base is molded about the inwardly extendingend of the tube by submerging it in a suitable molten resinous materialYconfined in a die of suitable configuration and hardening the resinousmaterial about the tube end.

It has been found that a shotgun cartridge having a case made inaccordance with this invention is a vast Improvement over the variousshotgun cartridges of the prior art because the advantageouscharacteristics of the laminated paper tube have been retained and, inaddition, the breech end of the cartridge has been improved. Incontradistinction to the paper shotgun cartridge having a metallic head,the shotgun cartridge of this invention is easily ejected from the gunchamber. In fact, it has been found .that basewads which do not providesucient obturation to permit their use in the metallic headed prior artpaper cartridge, as well as the better obturating wads, can besuccessfully utilized in a shotgun cartridge made in accordance withthis invention because the breech end of the plastic'headed cartridgedoes not become perma` nently expanded by the gases developed by theexplosion of the propellent charge. Cartridges having the breechstructure provided by this invention have been successfully reloaded andagain red without malfunctioning thereof. vThe plastic head also assiststhe basewad in providing rigidity to the breech end of the cartridge andthus assists in imparting the characteristic required for properinitiation of the 4priming charge. It is apparent,

therefore, that the cartridge provided by this invention hasadvantageous properties in addition to the important advantage ofproviding a substitute for the shotgun car- .Scrintion of ene embodimentof: this invention, 1a1 munie tubular-bodies nani be :cut therefrom iswoundabout ai 1 1 l g 1 1 1 f 1 suitable mandrel from; papercoated 'withcasein paste l 1 1 fand =isthen successively dried', sized, and cut tothe; re- 1 1 1 i i quired length in accordance with. well knownpractice;1 1 1 1 The .tube is then impregnated with paraffin or similar1wax= and.a i basewad `:is firstv compressed landA then positioned' 1 1 1.therein =in accordance with fknown methodsr except the 1 f 1 fbasewadfis positioned with the: bottom or: thatend there-1 iprdesignated -to .be :substantially f adjacent :the head ofi 1 z 1 1 1the cartridge; spaced inwardly1 fromfone endoftheitubei l 1 iA .mandrelis :now inserted iin the tube' and .the end .of

the tube: is forced intov fa; diei having?, a concave zeavity---1faround the iouterfed 1 1 against.: 1

about; c-

; tube .1, fol-ined; as .described hereinbefore is :placed on man restson basewad 7 fandpressure eirerted through r'nan pressure exertedthrough mandrel 2 is maintained until the plastic has cooled andsolidied. To facilitate removal of the cartridge case from the die, diecavity 5 is composed of two component parts, a cylindrical cavity 23 indie block 11 for forming the base of the head including the extractionrim and a cylindrical opening 22 through die block 9 for forming part ofthe base and the sidewalls of the cartridge head, as shown.

After the ethyl cellulose has cooled to below its melting point andpreferably to 8O or 90 C., die blocks 91and 11 which are fastenedtogether by pins 10 and 12 forming a friction iit in correspondingcavities in each of these parts are separated by moving die block 9 anddie 4 in a direction opposite to that designated by the arrow in Figurel. A primer assembly comprising a conventional battery cup 13, a primercup, a priming composition and an anvil is inserted with conventionalapparatus in the primer pocket in head or base 14 in the position shownin Figure 2 and the tubular body 1 is charged with propellant 1S, fillerwads 16 and 17 and projectiles 18. The end 19 of tube 1 is crimped overwad 20 to completely enclose the contents of the cartridge case.

Although in the foregoing, one embodiment of this invention is describedin detail, this invention is not limited to such details as numerousvariations can be made. Other suitably plasterized resinous materialssuch as, for example, melamine formaldehyde resins, urea formaldehyderesins, methyl methacrylate, ethyl methacrylate, polyamides, celluloseacetate and the like and molding compounds containing the same can beutilized for forming the cartridge head. Suitable plasticizers includedibutyl phthalate and the like. The laminated tube can be rolled with awater type adhesive such as described aboveA or the tube can be rolledwith a resinous material such as ethyl cellulose, polystyrene, syntheticrubber, such as iride@ having. ainetallic'head whemshortages of metal:

' Referring .now to the accompanying drawing. fora: de-fy l 1 therein:to fold rthat fpo'rtioa extending from the' bottorln 1 1 f of theibasewadinwardly at an :angieofiess than ninety I l f degrees.- Ehe.folded over 1 portion shoud- .be bent.

of' the, wad and dit :snuglythere 1 1 E E l :Die I4. sind .twopiececasting! die 9 =and=11f are assembled f as shown ini Figure il land.apretormed: disk'ot :a frnolding= 1 f 1 1cornpound; of: ethyl cellulose:having 1a mettingi point fof 1 .(11 is placed inciavity 15.; ''lie'ethyli cellulose 1 1its insertion; 'there-inf and assistsA mi secnrlngthe pruning as'sembiywithin the; head.= .it has' alsobeen; found thatthe; l l iunction of pin Siz when acting: as a= guide; pin to property 1position :the tubular body assembly; in? cavityi 5; is an :line ypor-t'an't one Las the goed extracting iprop'ertresof the clara tridgehaving a plastic :head are ati least partially .due to@r 1 1 1 isiheated ite yabouti 1.185 toi 226C? 2C; l A laminated paper 1 drel 2havinghandte 3 and isinserted in ydie v/ith the l ibend over iend; 6i 'of tube extending beyond the bottom 1 .end of basewad 7 finito :the:plastic-rnaterial.v 1 :Mandrel 2 1 l 1thei erxaeti alignment of fthe:tnbuiar body with the; headl 1 ;asf is nade possitxle by .thisinvention.-y -This aligrurlen'iz 1 can be' accomplished much moreaccurately than is possr-l 135 f. the tubular body fand head; of :thecartridge :are not 1 drel 2 against:r basewad 17 1und1; :the :assemblyIor tube! :1 and basewad; 7; is rnnvedifn fthe direction indicated bythey arrow in= Figure to a position in mold cavity 5 such; that atleast; about one-half. eff the basewad :7 and that pon-1 tion of itube 1l. thereabout is contained therein-.1 l Conicai ping t; :serves: toproperly aligntube; f1 lwith1cavity5; Sto'y stopi tubef1 at the proper=level therein and, :tu form -a-y 1 v 1 :pocket: for; later insertion of:the .primer assernhiy; The 1 I neoprene; and? the like;dissolvedrinasuitablesolvent or. 1 L i 1 1 while molten; :insome-instances,1 whenla resnnius'adhei f 1 y 1 sive is utilized forrolling; the. tube, a; suitable wax such f mensionsof conical pin Siprovision-can be made for cas 1 ing-aplastici tube-21; betweenpin-S-andtheWallof-eylm-v 1 plastic ltube =211 is smaller= in diameter than the.external concentrici .with the axis et: the: head; the' cartridgebeasiparain is included ingthe adhesive. Ait-subsequent wax- 1 1 v either.the kadhesive orthe: wax irnpregnationA step; .itz de -1 1 1 1 1 2sired.- vEvanescent f end closuressuch 1 as those formed s 1 from thetubular fbody for =a=r breakable top Wad can Lbe. i 1 1 1 1 util-izedinfcriinping: theloadedeartridge and other Aknown i i 1 f 1 sequeneezof`'steps can be followedineprelpraing. thel lami- 1 inzatied ltubularbedje-if desired.; AIt particularly advan.-` 1 1 1 tageous -to1foid2 thetube' about; the outer edge of :they l basewad and to press it snuglyagainst the. surfacel of thel g l l wadiat the: bend substantially asillustratedin the drawing. v i because isueh1a1 construction. resultsinf optimum strengthi 1 f and preventstheplastie iheadfrorn becomingsevered from;

;theztubefwhenthe -fshellistired= 1 1 1 1 1 1 1t is to lbeinoted,thatbj1-properly iecmtrollingl di `drietal channel 24 through basewad itapering 1 diameter of batters/1 cup E13 andis; expanded; thereby uponfble `when assemblyinga metallic head with ai tubularibody.; 1

properly 'aligned and :the axis; oftheprimger: assembiyfnot;

ling thereof againlstthe chamber walls renders extractionl 1 i of thered cartridge case diflcult. Pin 8, while preferably nearly conical,can, of course, be made in other suitable shapes such as a truncatedcone.

Having described the invention, what is claimed and desired to -secureby Letters Patent is:

1. In a gun cartridge, a case Vcomprising an oriticed basewad, alaminated paper tubular body compressibly' fitted over said wad andhaving one end thereof emd bedded at an open angle with said basewad inaset plastic head having a primer pocket, the plastic head comprising abase with an integral extraction rim thereabout, tubular sidewallsintegrally projecting from the base about said tubular body and intosaid open angle, respectively, in the region of the basewad and asmaller substantially cylindrical tube integrally projecting from thebase of the head as an extension for the primer pocket from said headinto the orice of said basewad, the smaller tube and primer pocket beingconcentric with` the. projecting tubular side walls and extraction rimor the plastic head.

2. The cartridge case of claim l wherein the tubular primer pockettapers from the pocket diameter of the opening in the base of the headto a diameter of less dimensions in the extension and a primer wedgedinto retention in said pocket.

3. A loaded gun cartridge having an oriced basewad, a powder charge, atleast one overpowder wad and a projectile charge contained in a casecomprising a ilexible laminated paper tubular body having one endthereof extending beyond said basewad and folded inwardly until pressedsnugly about the outer edge of said basewad t0 form an angle therewith,said end being retainably embedded in a pressure molded and set plastichead extending into said angle and carrying a primer press-fittedtherein for retention, said case having a crimped closure at the otherend of 4said body.

4. In the manufacture of gun cartridges, the process for making casestherefor which comprises providing a paper tube, placing a compressedoriced basewad within the tube in a position intermediate its endscloser to one end than to the other such that a portion of the tubeprojects from the bottom end thereof, folding said projecting portioninwardly toward the bottom of said wad around the outer edge thereof toleave 4said bottom and portion in spaced relationship, and forming aplastic head in situ about the folded projecting portion of the tubeembedded therein and at least said bottom of said basewad.

5. A shotshell cartridge case comprising a laminated paper tube, asubstantially Hat-bottomed centrally orifced basewad compressed withinsaid tube and disposed proximate one end of the tube, that end portionof the tube extending beyond the basewad being bent toward the center ofthe tube around the outer edge of said wad and forming an acute angletherewith, the bent portion of the tube being retainably embedded in aplastic head provided with a peripheral extension embracing an outerportion of the tube lateral to at least about half of the length of saidbasewad and with a centrally located extension embracing at least partof the interior surface of the basewad orice.

6. A method of making a shotshell case comprising providing a laminatedpaper tube, positioning a substantially flat-bottomed, oriiced basewadwithin said tube intermediate its ends with the bottom of said wadapproximate one end of the tube with a portion ofthe tube projectingbeyond said bottom of the basewad, folding the projecting portion of thetube inwardly thus forming a bent portion at an angle greater than andless than between the straight portion of the tube and the said bentportion of the tube, and molding and setting in situ a plastic headabout at least half way up that end of the tube containing the basewadwith a portion of the plastic head also being molded in the angleremaining between the basewad and the bent pro.

jecting portion of the tube.

References Cited in the le of this patent UNITED STATES PATENTS1,330,144 Sherman Feb. 10, 1920 2,426,289 Wallace Aug. 26, 1947 FOREIGNPATENTS 10,760 Great Britain June 2, 1894 394,037 Great Britain June 22,1933 914,780 France July 1, 1946 732,633 kGreat Britain June 29, 1955

